In the cultivation of plants such as tomato plants, the stems carrying tomatoes fold under the tomatoes' weight. In this case, the stem folds in such a way that the stem forms an upside down "V". In this position, the stem does not necessarily break but the side walls of the stem at the tip of the "V" collapse and the flow of sap is considerably restrained. Therefore, the tomatoes that had matured on such a fold stem, are smaller.
In order to prevent the stem of a plant from folding in an upside down "V" position, supporting frames are used. The goal of these frames is to curve a portion of the stem without collapsing its side walls and maintain the portion of the stem in a predetermined curvature so that while secured in the frame, it will keep growing normally in the predetermined curvature and provide normal flow of sap the flowers and tomatoes. Advantageously, the frame is installed on a young stem carrying flowers. Consequently, the fruit or vegetable well be growing on a stem already curved by the frame and will not make it fold in an upside down "V" position when they are getting heavy. There are three known types of supporting frames.
Frames of a first type have two coaxial rigid arc-shaped surfaces. The two surfaces are connected together in order to form a U-shaped cross-section. A portion of stem needs to be curved by a user in the curved orientation that corresponds to the arc-shaped surfaces before being inserted therebetween. The installation of a portion of a stem in such a frame is complicated and necessitates both hands of a user.
Known frames of a second type are partially flexible and have one convex arc-shaped surface with a hook at each end of the surface, each hook being opened in opposite directions. For installation, the stem is engaged in one hook, then laid over the convex portion of the arc-shaped surface and finally secured into the other hook in order to maintain a curved position that follows the convex portion of the arc-shaped surface. The second hook is the more flexible part of this kind of frame and helps the installation thereof. However, the installation of such frames remains complicated, necessitating both hands of a user.
Known frames of a third type are similar to the ones of the first type as they have two coaxial arc-shaped surfaces. However, the exterior surface is provided by a continuous member while the interior surface is provided by a plurality of fingers which are individually connected to one side of the continuous member. A cross-section of such frame also has a U-shape. Contrary to the frames of the first type, the continuous member is flexible. Straightening the continuous member results in spacing apart each of the fingers connected to it. This kind of frame can be slightly straightened for installation over a substantially straight portion of a stem. In this case, the stem does not need to be curved too much prior to being inserted into the frame. Therefore, the frame and the inserted portion of the stem will curve together after the installation as the continuous member recovers its initial curved shape. Such frames remain difficult to install, necessitating both hands of a user for their installation, and can slide along the stem or fall off.
There is a need for a frame which is easier to install and advantageously with only one hand. There is also a need for a frame that stays in place on the stem.